Can anyone help on this one please

Hi i`ve just recently bought a Nokia Lumia 1020 from china..


And joined windows 10 insider fast ring, i`ve had no problems upadating this phone from windows 8.1 to the latest

offering from microsoft, but for the life of me i cannot downgrade back to win 8.1


I`ve read all the tutorials i`ve done numerous soft & hard resets tryed different usb cables tryed different ports unistalled and reinstalled

WRT..


Now here is the thing that i don`t get,


When i connect my phone to my PC running win 7 WRT recognises my phone and then proceeds to tell me that there isn't

anything available on the server..


So i have held the volume button down & power pressed in, and restarted WRT to find my phone which it does and then proceeds to download a new rom.


But the new rom is for a different phone.. this is the rom downloaded by WRT

RM877 3051 50009 1451 1 RETAIL nam att 205 01 473928 prd signed.ffu

My installed rom is RM-875-apac_hong_kong_223